BitSynCom is a USA corporation, incorporated in the state of Nevada.
I don't see that entity on the website. Possibly that was deliberate. Is it listed once you do an account or order with them? You can't lien or attach BTC but does the company have any assets in the US that could be frozen by lis pendens? Since yufu is in the US the easiest route would be to serve him personally. He might have been deliberate in publicly stating he doesn't control the BTC sent in but you might be able to depose him under oath to get some answers but the process is very long for that if he fights it.
You should probably read the current render of avalon-asics.com before posting such dribble. It clearly says copyright Bitsyncom LLC. Not to mention, the waybackmachine records of the avalon-asics website during those orders. It's all very clear that Yifu and Avalon were operating as a Nevada-based domestic LLC with its managing member (Yifu) residing in Brooklyn.
I stand corrected as
http://store.avalon-asics.com/ doesn't have any of that. It's unlikely the US LLC has any assets which can be counted on for restitution but as a managing partner Yifu would certainly be exposed to US liability which actually makes it easier to get answers. Anyone who ordered can file a suit and serve him but if he chooses to fight it by the time you get to a depo the chips might be obsolete. Winning might require enshrining some new concepts regarding BTC as precedents as well. You can always call SEC since they have charged Trendon Shavers aka pirateat40 recently so they seem to be willing to take this kind of stuff up.
You bring up a good point; recoverability. If sued, what's the likelihood that the plaintiffs would actually receive restitution? Quite low. However, this isn't just a civil matter and it isn't just a matter for the SEC (traditionally they only deal with public companies) but rather one that hits the radar of the NYAG and FTC. The NYAG has a reputation for being incredibly tough, ever since Spitzer, and the FTC is a nightmare of its own. In short, Yifu & Co fucked up. They WILL have to answer in court, should they ever decide to step foot in the United States again.
To those mentioning the international aspect; this might actually draw out prosecution. My personal take is that Yifu will be summonsed in US court on interstate fraud charges and extradited accordingly. After all, when multiple countries want to prosecute, US almost always gets first hack at the bad guy.
The other reason why I think the SEC route is a waste of time is because Yifu wasn't directly soliciting funds to start or develop his company. The SEC cares more the sale of equity than anything else.